1. Field
The present disclosure relates to a thermosetting composition, and in particular relates to a thermosetting composition which is used as a sealing material for an organic electroluminescent device.
2. Description
Because organic electroluminescent devices have several advantages over its competitors, like being lighter, and thinner, and consuming less power with rapid response speeds and wide viewing angles, considerable research attention has been recently focused on development thereof.
A UV light curing epoxy resin is widely used in conventional organic electroluminescent devices. Because the epoxy resin is a brittle resin, it can not be used as a sealing material for a flexible substrate. Also, for surface-coated sealing requirements for a complete area, some problems may occur. For example, the organic materials of organic electroluminescent devices may degrade due to UV energy, the cathode and the organic layer of organic electroluminescent devices may peel due to rapid stress changes during curing processes of the epoxy resin, or the epoxy resin may not completely cure during the curing process.
In order to mitigate the above problems, a thermosetting resin has been disclosed. JP 10-135255 provides a thermosetting resin, wherein anhydride is used as a curing agent, and imidazole is used as a curing accelerating agent. However, the thermosetting resin is cured at a high temperature (about 170° C.). JP 2006-228708 provides a thermosetting resin, wherein anhydride is used as a curing agent, and 2,4,6-tri(dimethy phenol) is used as a curing accelerating agent. However, a curing reaction during the curing process must be conducted at a temperature of 100° C. for more than one hour.
Accordingly, there is a need to develop a thermosetting composition which may be used as a sealing material for organic electroluminescent devices, wherein the thermosetting composition does not adversely affect organic electroluminescent devices and may be used with flexible substrates.